The aging brain shows less flexible reallocation of cognitive resources during dual-task walking: A mobile brain/body imaging (MoBI) study

Abstract

Aging is associated with reduced abilities to selectively allocate attention across multiple domains. This may be particularly problematic during everyday multitasking situations when cognitively demanding tasks are performed while walking. Due to previous limitations in neuroimaging technology, much remains unknown about the cortical mechanisms underlying resource allocation during locomotion. Here, we utilized an EEG-based Mobile Brain/Body Imaging (MoBI) technique that integrates high-density event-related potential (ERP) recordings with simultaneously acquired foot-force sensor data to monitor gait patterns and brain activity concurrently. To assess effects of motor load on cognition we evaluated young (N=17; mean age=27.2) and older adults (N=16; mean age=63.9) and compared behavioral and ERP measures associated with performing a Go/No-Go response inhibition task as participants sat stationary or walked on a treadmill. Stride time and variability were also measured during task performance and compared to stride parameters obtained without task performance, thereby assessing effects of cognitive load on gait. Results showed that older, but not young adults’ accuracy dropped significantly when performing the inhibitory task while walking. Young adults revealed ERP modulations at relatively early (N2 amplitude reduction) and later (earlier P3 latency) stages within the processing stream as motor load increased while walking. In contrast, older adults’ ERP modulations were limited to later processing stages (increased P3 amplitude) of the inhibitory network. The relative delay and attenuation of ERP modulations accompanied by behavioral costs in older participants might indicate an age-associated loss in flexible resource allocation across multiple tasks. Better understanding of the neural underpinnings of these age-related changes may lead to improved strategies to reduce fall risk and enhance mobility in aging.

Neuroimaging of Human Balance Control: A Systematic Review

“…These differences in ERPs were not accompanied by performance decrements in dual-task conditions, suggesting the use of compensation mechanisms to appropriately allocate attentional resources to perform both tasks (De Sanctis et al, 2014). Malcolm et al (2015) also used a go/no-go task in young and older adults while walking or sitting, finding a decreased N200 amplitude for dual-task condition and earlier P300 latency over the Cz, FCz, and CPz electrodes in young adults, similar to De Sanctis et al (2014). Young adults exhibited a decreased N200 latency, while older adults showed an increase in P300 amplitude, indicating that older adults may have less flexibility of resource allocation in multi-task conditions (De Sanctis et al, 2014).…”

Self‐Reported Head Trauma Predicts Poor Dual Task Gait in Retired National Football League Players

“…However, reported links between sports‐related head trauma, brain structure, brain function, and/or health outcomes have been derived largely from cross‐sectional studies and/or comparisons to suboptimal control groups. Longitudinal studies that include multimodal mobile imaging of numerous aspects of dual task gait performance and/or habitual physical activity coupled with physiologic, biomarker, and neurocognitive testing are thus needed to establish whether a history of sports‐related head trauma alters the time course of changes in brain health, and whether such changes underline reductions in gait and other cognitive–motor functions over time.…”

Mobile Brain/Body Imaging of cognitive-motor impairment in multiple sclerosis: deriving EEG-based neuro-markers during a dual-task walking study

“…In addition, younger adults increased their stride time, thereby making fewer, longer steps, while performing the response inhibition task. In contrast, older adults showed no N2 modulation, no change in stride time, and a decrement in their Go/NoGo performance under dual-task load 28 . We concluded that the nogo-N2 modulation reflected flexible cortical resource allocation under increased task load.…”

“…Based on our prior work, we predicted that some individuals with MS, similar to their healthy control counterparts, are able to adapt information processing to increased dual-task load and thereby reduce costs typically associated with performing two tasks simultaneously 50,51 . We have previously shown that adapted processing, indexed by load-related N2 modulation, was accompanied by better dual-task performance 28 . We predicted a linear relationship with, stronger N2 modulation being linked to less DTCs.…”

“…We applied a dual-task MoBI approach 5,11,28 to record brain activity in conjunction with gait and Go/NoGo performance measurements, to gain insights into the cortical correlates of dual-task processing in multiple sclerosis. Based on our prior work, we predicted that some individuals with MS, similar to their healthy control counterparts, are able to adapt information processing to increased dual-task load and thereby reduce costs typically associated with performing two tasks simultaneously 50,51 .…”